Compilation Error on Service Studio


I'm having a persistent compilation error on a on-preimises with a developed .xif. The error message states:

Internal Error

Compilation Error.
fatal error CS0009: Metadata file 'c:\Program Files\OutSystems\Platform Server\share\NAVExposer\full\bin\NAVExposer.dll' could not be opened -- 'The process cannot access the file because it is being used by another process.'

State: Second stage compilation

I am able to correctly compile if I either reboot the server or republish the .xif.The application is running fine.

Any thoughts?

Thank you

Try restarting the Out systems services and IIS. I hope this will resolve your problem.




It solves once. I am able to correctly deploy immediately after a reboot. Then the error persists.


I'm evolving on this issue and could narrow it down to the web services.

If I delete all web services developed on the eSpace, everything goes fine. But, even adding an empty coded REST will cause the exact same error.

Please, anyone with any idea?

Thank you,




Just to wrap this up, we ended up realizing the antivirus was the culprit. Once making an exception, avoiding it to check the Outsystems Platform installation folder, everything went smoothly.